Plural turbine hydrokinetic torque converter



Dec 22, 1964 v. J. JANDASEK 3,162,016

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Dec. 22, 1964 v. J. JANDASEK 3,162,016

PLURAL TURBINE HYDROKINETIC TORQUE CONVERTER Filed June 4, 1963 2 Sheets-Sheet 2 VL AD/ M// J.JANDA$EK INVENTOR;

United States Patent Oiiice anni Patented Dec. 22, 1964 3,162,016 PLURAL TURBNE HYDROKENE'HC TRQUE CNVERTER Vladimir J. Jandaseir, Dearborn, Mich., assigner to Ford Motor Company, Dearborn, Mich., a corporation of Delaware Filed .inne 4, 1963, Ser. No. 285,516 3 Claims. (Ci. S0-54) My invention relates generally to multiple element hydrokinetic torque converter mechanisms, and more particlarly to a hydrokinetic torque converter mechanism having a compound turbine that is situated within a torus circuit with an impeller and compound stator members. It is capable of establishing a relatively high degree of torque ratio carry-out throughout an increased speed ratio range and is adapted especially for drive-lines for engine powered automotive vehicles.

In a hydrokinetic unitof this type, the impeller member functions to increase the moment of momentum of the fluid that traverses the torus circuit. As the fluid passes through a turbine section of the mechanism, the moment of momentum is decreased, and this causes a turbine torque to be developed. For this reason, the flow that passes from the exit section of the turbine is passed through a turbine section of the mechanism, the moment of momentum is decreased, and this causes a turbine torque to be developed. For this reason, the flow that passes from the exit section of the turbine is passed through a stator section situated at the flow exit region to redirect the uid flow and increase the tangential component of the absolute uid ow velocity vector. The entrance angle of the fluid iiow that enters the next succeeding bladed member thus is in a direction which would make an augmentation of the delivered torque possible as the fluid circulates through the circuit.

In the disclosed embodiment of my improved mechanism I have provided a second impeller stage situated between the ow exit section of the lirst stator stage and the entrance section of the second turbine stage. This results in an increase in the moment of momentum of the liuid before it enters the second turbine stage. This, in turn, results in increased operating eiciency and torque ratio and a more satisfactory converter size factor characteristic, the size factor being dened as the impeller speed divided by the square root of the impeller torque. I contemplate that this will result in a relatively rapidly rising engine speed during the acceleration period.

My improved mechanism includes also a third turbine section situated at the how entrance region of the main inpellcr. The angularity of the blades of this third turbine section can be adjusted so that an optimum blade angle will be provided to satisfy the varying angularity of the absolute uid flow velocity vector at this point in the torus circuit. Unlike the entrance region of the second impeller stage, the first impeller stage receives uid directly from the exit region of the preceding turbine stage rather than a stator stage. But the adjustable feature of the third turbine stage still makes it possible to positive torque contribution from the third turbine stage mthout causing an unfavorable shock loss condition at the entrance region of the rst impeller stage.

The provision of an improved hydrokinetic torque converter mechanism of the type above set forth being a principal object of my invention, it is a further object of my invention to provide a compound torque converter mechanism having iiuid turbine stages situated in series within a common circuit so that a positive torque contribution from each can be obtained throughout a wide speed ratio range.

F or the purpose of describing my invention more particularly, reference will be made to the accompanying drawings, wherein:

FEGURE l shows in cross-sectional form a compound torque converter having the features of my invention; and

FIGURE 2 is a schematic blade diagram and vector representation of the uid iiow vectors within the torus circuit.

Referring first to FIGURE l, numeral 10 designates a flange carried bythe crankshaft of an internal combustion vehicle engine. It is bolted by means of bolts l2 to the hub of a drive plate i4. This drive plate in turn is bolted by bolts 16 to the outer periphery 18 of an impeller shell part 20. A second impeller yshell part 2.2 is secured at its periphery 24 to the periphery 18 and to the periphery of the drive plate 14. A starter ring gear 24 can be carried by the shell part 22 as indicated.

Shell part 22 is in the form of a torus and is provided with a hub 2.6 that may be journaled in a conventional fashion within an opening formed in thev transmission housing as shown.

The hub of shell part 2) is welded to a pilot member 28. This member 2S inturn is received within an opening 30 situated within the crankshaft flange l0. o

The radially inward portion of the shell lpart 22 has secured thereto the inner margin 32 of an inner impeller shell 3d. The outer margin of the shell 34 is secured by spot welding to a radially outward portion of the inner surface of shell part 22 as indicated at 36.

An inner impeller shroud 38 is secured to the inner margins of impeller blades 40. These blades define radial outflow passages. A first turbine element is identified by reference character 42. It includes blade elements 44 that are situated at the ow exit section of the blades 40. Blades d4 are situated between a rst shroud 46 and asecond shroud 43, the former being secured by screws 50 to a torque transfer member 52. This member 52 in turn is secured to a first shroud 54 for a third turbine section identified by reference character 56. vThis turbine section comprises blades 53 situated at angularly spaced locations with the torus circuit. Blades 58 are mounted upon adjustabie blade supporting shafts 6i) which are received through openings formed in the shroud 54.

A second shroud for the third turbine section is shown at 62. It comprises a rst part 64 in the form of an annular cylinder and a second part 66. The two parts 64 and 66 are joined together by screws 63. Openings 70 deiined by the mating surfaces of the parts 64 and 66 receive shafts 60.

Part 66 includes an extension 72 which is journaled by means of bushing '74 upon a relatively stationaly stator shaft 76. This shaft in turn can be connected n a conventional fashion to the transmission housing, not shown.

Parts 64 and 66 cooperate to define an annular cylinder 78 within which is received slidably an annular piston 8l?. This piston Sil and the cylinder '78 cooperate to define a pressure chamber $2. Chamber 82 is in liuid communication with a pressure port S4 which in turn communicates with a radial passage 36 formed in stator sleeve shaft '76.

his passage S6 in turn communicates with an annular passage SS that is formed within the interior of shaft 76. Fluid pressure from a suitable control valve system, not shown, can be supplied to passage 88, and this in turn controls the pressure in passage S2.

A closure member 90 is secured by means of a snap ring 92 to the open end of the cylinder 78. It is apertured, as shown at 9d, so that the pressure that exists within the torus circuit will be made available to urge the piston Sti in a left hand direction as viewed in FIG- URE l. Thus by controlling the pressure balance across the piston Si?, the position of the piston can be controlled as desired.

The radially inward extremity of the shafts Gli-are offset and are received within an annular groove 96 formed in piston 80. As the piston l is shifted axially, the shafts 5t! then will oscillate about their respective radial axes and cause a corresponding adjustment of the angularity of the blades 53.

A thrust washer 9S is situated between closure member gli and the hub portion of the impeller shell parts 22.

The shroud t8 of the first turbine section 44 is connected to a torque transfer member 1d@ which extends generally in an axial direction. This member in turn is connected to web elements 1M which extend through the torus circuit. The radially inward ends of the elements 102. are connected to a boss 164 by means of a bracket 106. This bracket can be secured to the boss 16d by bolts S.

The web elements 102 may be designed with an aerodynamic cross section to reduce to a minirnurn the degree of resistance to the toroidal iluid flow.

Boss 164 is carried by an inner shroud 11h of a second turbine section 112. This turbine section includes blades 114 which are secured at their inner magins to the shroud 11i). An outer shroud 11b is secured to the outer margins of the blades 114. The shrouds 11@ and 116 cooperate with the blades 114 to define radial iniiow passages.

The inner margin 113 of the shroud 116 is secured by bolts 126 to a hub member 122 and to a second hub member 124. Member 124 in turn is internally splined to an externally splined portion 126 of a turbine shaft 128. A reaction disc 13) can be bolted by a bolt 132 to the end of the shalt 128, as indicated, thereby holding the `shaft 12S axialiy fast with respect to the turbine hub member 124. Shaft 123 can be journaled within the stationary sleeve shaft 76 by bushings, one of which is shown at 134.

A rst stator section 136 is situated at the flow exit section of the iirst turbine section 44. It includes blades 13S that are situated within the torque transfer member 149i). These blades 13@ are connected to an inner shroud 140 in the form lof an annular ring. This ring 14% is connected to a web 142 which is secured at its inner margin to an annular ring 144. Ring 144 in turn is secured to the outer ends of the webs 146.

Webs 146 include a shroud in the form of an annular ring 150 which is secured by rivets 152 to the outer race 154 of an overrunning coupling 155. An inner race for the coupling 156 is dened by the outer surface of the stator shaft 76. It includes rollers or sprags 158 that are situated between the two races, the outer one of which may be cammed if the elements 158 are in the form of rollers.

Located at the dow exit region of the secondary turbine section 112 is a second stator section 165i which includes stator blades 162 located between a iirst shroud 164 and a second shroud 166. These blades 162 are mounted upon blade supporting shafts 168 which are received through cooperating openings formed in the shroud 164 and shroud 165. Shroud 166 in turn is delined by a first part in the form of an annular ring 179, and a second part 172. These parts are held together by bolts 174, and shafts are situated within cooperating openings deiined by the mating surfaces of parts 172 and 170.

Part 172 delines an outer race for a Second overrunning brake identied by reference character 17e. This brake 175 may include sprags or rollers 17S which are situated between the outer surface of sleeve shaft 76 and the inner surface of the outer race. If elements 175 are in the form of rollers, the outer race can be cammed in a conventional fashion.

Brakes 156 and 17d inhibit rotary motion of the stator sections in one direction, but they" will permit freewheeling motion of the stator sections in the opposite di reetion, which corresponds to the direction of rotation of the impeller.

The impeller is formed in two sections that are generally identified by reference characters 18@ and 182. Section 182 includes a race 184 which is bolted or otherwise secured to the inner periphery of shell part 22. Suitable bolts 136 can be provided for this purpose.

rnepeller blades 1% are carried by the shroud 184. These blades carry an inner shroud 13S. Blades 186 are situated directly adjacent the ow entrance section ot the turbine section 112 and rotate in unison with the blades 4b.

ln FIGURE 2 I have illustrated in schematic form the blades of the converter mechanism of FIGURE l. They are illustrated in the lform of a cascade by unwrapping the torus circuit. The fluid flow then may be represented by vectors that extend in a right hand direction as viewed in FGURE 2. While the direction of rotation of the impellers and the turbines can be represented by vectors that extend downwardly as viewed in FIGURE 2.

The direction of the absolute uid iiow velocity vector at the entrance section of the second impeller section will vary depending upon the relative speed ratio that exists. At stall or zero speed ratio, this vector is represented by the symbol A as viewed in FIGURE 2v At a rela tively high speed ratio, however, the vector will change direction as indicated by the symbol B in FlGURE 2. 1t is apparent, therefore, that the most desirable blade angie for a minimum shock loss condition will be some compromise value between the angle of the vectors at stall and the angle of the vectors under cruising conditions. In the particular embodiment shown, the blade angle may be approximately The moment of momenum of the fluid changes as it passes through the second impeller section. This in turn is a function of the torque acting upon the secondary impeller section. The change in the moment of momentum, however, is equal to the moment of mementum of the iluid that leaves the secondary impeller section less the moment of momentum that leaves the exit section of the preceding lirst stator section. This is true since the moment of momentum at the entrance of the second impeller section is equal to the moment of momentum of the iluid at the exit of the first stator section.

Shown also in FIGURE 2 is a vector diagram showing the characteristics of a particle of fluid at the exit of the rst stator section and at the exit of the second impeller section. The symbod F' represents the toroidal fluid flow vector at the secondary stator exit. The uid velocity vector measured along the stator blade itself in indicated by the vector W. This also equals the absolute uid iiow velocity vector V' since the stator is stationary during operation in the torque conversion range at low speed ratios. The vertical component of the vector sum is equal to the vector shown at S0. This vector is the tangential uid iiow velocity vector at the secondary stator exit.

The corresponding vectors for the exit of the secondary impeller section also are shown in FIGURE 2. The toroidal flow vector is' shown at fo. Since the blade angle itself is approximately 90, this vector also represents the vector for the uid ow wo along the blade itself.

The rotational vector due to the driving motion of the impellers is shown by the symbol u. The Vector sum is shown at v0. The exit blade angle itself is preseented by the symbol v.

The tangential component of the absolute fluid ow velocity vector is shown at so. It will be apparent from a comparison of the two vector diagrams thus described that the tangential component 4of the absolute iluid iow velocity vector is increased, which means that the secondary impeller section provides a definite torque contribution. It follows from this, therefore, that the moment of momentum of the iluid that enters the second turbine section will be greater than it would be if the secondary impeller section were not located strategically within the circuit in this fashion. The turbine torque, therefore, will be increased since the total effective change in the moment of momentumiof the fluid yas it passes through the second turbine section will be magnified to the extent that the inlet moment of momentum is increased.

Corresponding vectors for the second stator section and the third turbine section are indicated also in FIG- URE 2.

At the exit of the second stator section, the toroidal iiuid fiow is represented by the vector F0". The flow along the blade is represented by the vector W0". The vector sum is equal to V0.

The tangential component of the absolute fluid flow velocity is designated by the symbod S0.

The blade angle at the exit of the second stator section is designated by the symbod r". The coresponding angle for the first stator section is 'r'.

If we consider for the time being that the blades of the third turbine section assume the dotted line position shown in FIGURE 2, the tangential component of the absolute iiuid flow velocity vector can be represented as shown at So. Under stall conditions and at very low speed ratios, the vector So is smaller than the vector So since the rotational vector UD will not be available to augment the Vector sum. It follows from this, therefore, that a positive driving torque will be imparted to the third turbine section. This torque supplements the torque of the rst turbine section and the combined torque of the turbine sections is distributed to the turbine shaft 128.

As the speed ratio increases, however, the fiow entrance vector at the inlet of the third turbine section will shift between the two extremes represented by the letters C `and D. It will be apparent, therefore, that at increased speed ratios the moment of momentum of the fluid that passes through the third turbine section will decrease. If the blades were held stationary, a negative torque would be developed by the iluid which would subtract from the net turbine torque made available to the shaft 128. To overcome this characteristic, the blades of the third turbine section are adjustable in the manner previously described. At increased speed ratios, the angularity of the blades can be shifted to the full line position shown in FIGURE 2. Under these conditions, a positive torque contribution will be provided by the third turbine section throughout an increased speed ratio range.

Provision may be made for providing an infinitely variable adjustment of the blades 58 of the third turbine section. In this way, optimum performance can be obtained throughout the entire speed ratio range and the need for 'making design compromises is then avoided. This infinite variation in angularity can be accomplished by providing a controlled pressure to the chamber 82 of the blade adjusting servo. This pressure can be obtained by a valve system that is sensitive to engine torque demand as well as the driven speed of the driven member.

By employing a turbine arrangement with a third turbine section situated adjacent the entrance section of the impeller, the converter stall speed will be reduced to any desired value depending upon the blade geometry that is chosen. The impeller speed will increase rapidly, however, as the speed ratio increases, and a relatively rapidly rising size factor characteristic then results.

Any torque augmentation that is obtained by the third turbine section will result, of course, in a decrease in the moment of momentum of the uid that passes through the third turbine section. This then necessarily means that the tangential component of the absolute uid iiow velocity vector in the direction of rotation of the impeller will be decreased. It is because of this that the impeller speed will be reduced at stall. The torque contribution of the third turbine section fades, however, as speed ratio increases. The influence of the third turbine section upon the magnitude of the absolute fluid iiow velocity vector at the entrance section of the first impeller section thus progressively diminishes. The size factor then will increase rapidly upon increased speed ratios and will not remain relatively uniform, as in conventional arrangements, prior to the time the coupling range is achieved. The peak engine torque then can be reached quickly during acceleration.

In FIGURE 2, Uo represents the rotational vector due to rotation of the third turbine section. The blade angle itself is represented by the symbol 1- and the vector sum of the rotational vector and the flow W0 along the blade is represented by sym-bol Vo. The toroidal fluid flow, of course, is represented by the symbol Fo.

Having thus'described preferred embodiments of my invention, what I claim and desire to secure by United States Letters Patent is:

1. A hydrokineticA torque converter mechanism comprising a Vbladed impeller, a compound bladed turbine assembly and a compound bladed stator assembly situated in toroidal uid iiow relationship within a common torus circuit, said turbine comprising -a-t least three bladed sections, and said stator comprising two bladed sections, the first :turbine section being located at the flow exit region off said impeller, the first stator section being located at the flow exit region of said first turbine section, the second stator `section being located at the flow exit region of the second turbine section, said impeller having a first portion loca-ted at a. radial outflow region of said circuit and a second portion in a radially outward region of said circuit adjacent a bladed section of said turbine, the second turbine section being located at a radial infiow region of said circuit, the third `turbine' section being located at the ow entrance region of said impeller at a radially inward location, and servo means for adjusting the angularity of the blades of said third turbine section, said servo means comprising a hub defining a cylinder, a piston in said cylinder defining in part a fluid working chamber, and a mechanical connection between said piston and each blade of said third turbine section whereby the angularity of the latter can be controlled.

2. A hydrokinetic torque converter mechanism comprising a compound impeller, a compound turbine and a compound stator situated in toroidal fluid iiow relationship Iwithin a common torus circuit, said turbine comprising at least three bladed sections, said limpeller comprising two bladed sections and said stator comprising two bladed sections, the first turbine section being located at the flow exit region of the iirst impeller section, the iirst stator section being located between the first turbine section and the second impeller section, the entrance region of the second turbine section being located adjacent the fiow exit region of the second impeller section, the second stator section being located at the flow exit region of the second turbine section, the first impeller section being located at a radial outflow region of said circuit, the second turbine section being located at a radial inflow region of said circuit, the first turbine section, the irst stator section :and the second impeller section being l0- cated at ya radially outward region of said circuit, each impeller section being connected together for rotation in unison, the -third turbine section being located between said second stator section and the fiow entrance region of said first impeller section at a radially inward location, said third turbine section comprising a hub defining a cylinder, a piston in said cylinder defining in part a iiuid working chamber, and a mechanical connection between said piston and each blade of said second turbine section whereby the angolari-ty of the latter can -be controlled.

3. A hydrokinetic torque converter mechanism comprising a compound impeller, a compound turbine and a compound stator situated in toroidal fluid flow relationship within a com-mon torus circuit, said turbine comprising at least two bladed sections, said impeller comprising' two bladed sections and 'said stator comprising two bladed sections, the first turbine section being located at the ow exit region of the iirst impeller section, the lirst stator section being located between the rst turbine section and the second impeller section, the entrance region of the second turbine section' being located adjacent the iiow exit region of the second impelier section, the second stator section being located at the iiow exit region of lthe second turbine section, the rst irri-pellet section being located at a radial outiiow region of said circuit, the second turbine section being located at a radial inflow region of said circuit, the first turbine section, the rst stator section and the second irnpeller section being lo cated at a radially outward region of said circuit, each impeller section being connectedl together for rotation -in unison, first overrunning brake means for inhibiting rotat-ion of the first stator section against rotation in one drection and for permitting free'running motion in the opposite direction, second overrunning brake means for inhibiting rotation of the second stator section against rotation in said one direction while accommodating freerunning motion thereof in said opposite direction, a third .turbine section mechanically connected to said rst and second turbine sections, said third turbine section being located at a radially inward region lof said circuit adjacent the tiow entrance region of the irst impelier section, and duid pressure operated servo means for .adjusting the angularity of Vthe biades-of said third turbine section to conform with variations in the anguiarity of the absolute fluid flow lVelocity vector at said radially inward region, said servo means comprising a control pressure feed passage communicating therewith for distributing control pressure thereto.

References Cited by the Examiner UNTED STATES PATENTS 2,339,483 U44 Iandasek 60-54 2,339,484 U44 Jandasek 60-54 2,762,196 9/56 Uiiery 60-54 2,762,197 9/56 Uilery 60-54 2,893,266 'H59` .Kelley 60-54 X 3,083,589 4/63 Knowles et a1 60-54 X FOREIGN PATENTS 738,699 10/ 55 Great Britain.

JULIUS E. WEST, Primary Examiner. 

1. A HYDROKINETIC TORQUE CONVERTER MECHANISM COMPRISING A BLADED IMPELLER, A COMPOUND BLADED TURBINE ASSEMBLY AND A COMPOUND BLADED STATOR ASSEMBLY SITUATED IN TOROIDAL FLUID FLOW RELATIONSHIP WITHIN A COMMON TORUS CIRCUIT, SAID TURBINE COMPRISING AT LEAST THREE BLADED SECTIONS, AND SAID STATOR COMPRISING TWO BLADED SECTIONS, THE FIRST TURBINE SECTION BEING LOCATED AT THE FLOW EXIT REGION OF SAID IMPELLER, THE FIRST STATOR SECTION BEING LOCATED AT THE FLOW EXIT REGION OF SAID FIRST TURBINE SECTION, THE SECOND STATOR SECTION BEING LOCATED AT THE FLOW EXIT REGION OF THE SECOND TURBINE SECTION, SAID IMPELLER HAVING A FIRST PORTION LOCATED AT A RADIAL OUTFLOW REGION OF SAID CIRCUIT AND A SECOND PORTION IN A RADIALLY OUTWARD REGION OF SAID CIRCUIT ADJACENT A BLADED SECTION OF SAID TURBINE, THE SECOND TURBINE SECTION BEING LOCATED AT A RADIAL INFLOW 